An electronic transaction processing system performing a deposit and/or a withdrawal of digital cash between a customer and a banking facility includes a customer money card storing digital cash of the customer, a bank money card storing digital cash of the banking facility and an escrow card storing transaction information with respect to a transaction with digital cash between the customer and the banking facility. A transaction is processed by renewing digital cash stored in the customer money card and in the bank money card in response to the amount of the transaction, and transaction processing is performed after storing each balance information of digital cash stored in the customer money card and in the bank money card and the amount of the transaction in the escrow card.